Chemical reactor systems that make use of liquid propagation have a large number of applications, including production of chemical components, synthesis of nano-particles, separation and/or extraction of components, etc.
In separation techniques based on liquid propagation, use is typically made of the difference in affinity of various substances with a mobile phase and a stationary phase and/or of the difference in partition coefficients for partitioning of components. As each substance has its own “bonding power” to the stationary phase, they will be moved along faster or slower with the mobile phase and as such, certain substances can be separated from others. In principle, it is applicable to any composition, having the advantage that no evaporation of the material is required and that variations in temperature only have a negligible effect.
A specific example of a separation technique for separating mixtures is chromatography, for example in order to be able to analyse these accurately. A large variety of types of chromatography exists, such as gas chromatography, gel chromatography, thin-layer chromatography, adsorption chromatography, affinity chromatography, liquid chromatography, etc.
During liquid chromatography, a phase that is interesting for analysing is typically captured from the mixture first, to then be able to take it to a detector or inject it into an analysing column. Capturing the phase of interest typically happens in a trapping column, in which use is made of the difference in affinity of various substances with a mobile phase and a stationary phase and/or the difference in partition coefficients for partitioning of a mixture in its components.
As analysis often needs to happen on small quantities of specimen, it is important that when the specimen flows through the device, all useful parts of specimen are handled as efficiently as possible, and without loss. In a traditional device, the various components in the system, such as for example the trapping column and the analytical column, are typically coupled together using connectors and valves. Switching these valves then allows to control the liquid flow during the various actions such as loading of the specimen, separating of liquid phases of the specimen and injecting of the separated phase of interest to a detector or analytical column. However, due to their position in the specific configuration of devices in the state of the art, these valves and connectors often also have the disadvantage that a part of the specimen stays behind in dead volumes of or introduced by the valves. This may not only have a negative effect on the amount of specimen available but may also lead to contamination of the various separated phases, causing separation to happen less efficiently. In addition, in the traditional arrangement, these dead volumes introduce a significant plug broadening during the injection step causing the analytical separation to be negatively affected. The smaller the volumes used or worked in, the larger the impact will be.
In other words, there is room for improvement.